I purchased a total of six(6) G-Technology G-RAID THUNDERBOLT 8TB external drives on 04/06/2013

I have a problem with 2 of the units that I think can be covered with the 3 year factory warranty.

Unit 1 problem – one drive has hardware problem that can not be repaired according to the message for OSX’s Disk Utility. I cannot use this drive because it will not mount at all.

Unit 2 problem- has trouble being powered up. It intermittently takes several cycles of powering up before it will fully initialize and mount. I cannot use this drive for fear it will completely stop powering up at any time.

FYI – I have tried with different sets of thunderbolt cables and different power supplies and power cables on both units with the same results.

What steps would be recommended to get these two units repaired or replaced?

Thanks for posting. You mentioned with the first drive that one of the modules within it cannot mount, is it also unable to format? As for the second drive since you have already tried multiple power adapters with it the problem would seem to be with the unit. You can file a RMA to have the drive replaced from our site. I will include a link below to that form. If the module in the first drive is unable to format then I would suggest filing a RMA for that unit as well. You can send in just the drives for the RMA and hang on to all cables. http://www.hgst.com/warranty/index_gtech_serial.do

Though the RMA lists to include cables it is not required, since you have tried with multiple power adapters and the problem persists the power adapter is most likely fine. You can send it in if you wish and it will be replaced. Definitely hang on to the tunderbolt cable. Our early models did not come with the cables and can't guarantee you would get a replacement if it was sent in.